Asphalt-based roofing materials, such as roofing shingles, roll roofing, and built-up roofing, are installed on the roofs of buildings and residential dwellings to provide protection from the elements. The use of adhesives, including asphaltic compounds, to provide a bond between roofing shingles when they are attached to a roof is well-known. During a typical shingle manufacturing process, a pattern of adhesive is applied to the headlap portion of the shingles so that the tab portion of the subsequently laid course of shingles on the roof will adhere to the headlap portion of the lower course. This seal is to help prevent wind from uplifting the shingles.
To seal properly, most conventional sealants or adhesives require relatively high roof temperatures. Indeed, many conventional adhesives require roof temperatures of about 135° F. or higher to activate the sealant. In relatively colder climates, these roof temperatures may not be reached until seasons subsequent to installation, which conceivably could be months later. Thus, under conditions where relatively low temperatures do not permit proper sealing of the adhesive, the shingles may not be properly sealed. Another problem with conventional sealants is that colder temperatures tend to cause the sealant on the sealed shingles to become brittle and crack, resulting in bond failure.
A further problem associated with conventional sealants is that the sealant may bond the shingles together when they are in a packaged or bundled formation, such as, for example, for shipping and storing. A shingle having thereon an overly aggressive sealant will not only bond to the tab portion of the shingle when placed on a roof, it will also bond to the release tape of the adjacent shingle within the packaged shingle bundle. Such bonding may not only damage the shingle as the shingles are pried apart, it may cause frustration to the consumer trying to separate the shingles.
Although attempts have been made to address the temperature sealing problem of conventional adhesives and the over aggressiveness of the sealants, there remains a need in the art for an asphalt sealant that provides a quick and good seal at low roof temperatures, that is not overly aggressive so as to bond to the release tape in a packaged formation, that has a high bond strength to provide good resistance to shingle uplift, that does not pose any additional health or safety issues, is cost effective, and where the performance of the sealant is sustainable over time.